Displaying Data

[ghostz13]

Hi all,

I'm currently sending voltage levels from my 10 bit ADC to my com port. The microcontroller then converts the ADC output to a float and sends it through the serial port using the statement

printf("%04.3f\n\r",result);

and in hyperterminal i receive values like 2.500 2.501 2.501 etc etc..

I've tried using Visa and plotting the info but i keep getting problems. Pls refer to image.

I'm getting the correct readings from the READ STRING in indicator (2.500 2.501 2.501) but my VOLTAGE READINGS gets the first reading correct 2.500 then flats out at 0 from then on.....


image

Message Edited by ghostz13 on 02-27-2007 02:02 AM

[K C]

Hi,

I posted a COM vi that I always use for serial communication. Take a look.

In your VI your are reading x bytes every few milliseconds without knowing how many and if there are bytes ready with the time-out you specified earlier.

Let me know if this VI works

[ghostz13]

Hi KC,

Eric has been helping me out http://forums.ni.com/ni/board/message?board.id=170&message.id=211464&view=by_date_ascending&page=2
and it kind of works for me except for the way it displays as bar charts. Could you teach me how to change it to a single line graph such like the output from an oscilloscope.


Regards,
Gerard

[K C]

Hi Gerard,

Try it with a waveform chart.

[ghostz13]

Hi KC,

I'm currently using a waveform chart to plot my values. Problem is that it plots one point, goes to zero, plots another point and results in the "bar charts" i mentioned.

Regards,

Gerard

[K C]

Hi Gerard,

Indeed you mentioned the ‘bar charts’ but with fast reading …..

Right click on the plot legend of your graph and select ‘bar plots’ Here you can select the type of plot. But what you want is the default, so you must have changed this before 

Message Edited by K C on 03-06-2007 09:05 AM

[ghostz13]

Hi KC,

The waveform chart now displays line values. But I'm having problems changing the X axis time scale. I've tried changing scalefit, increment, maximum, minimum, multiplier through a knob connected to the property nodes with no success. Any other way to do it ? Thanks!

Regards,

Gerard

Message Edited by ghostz13 on 03-12-2007 09:52 PM

[K C]

Hi Gerard,

Can you post the VI you made ?

[ghostz13]

Hi KC,

I've posted it on the last post here http://forums.ni.com/ni/board/message?board.id=170&message.id=211464&view=by_date_ascending&page=3

Regards,
Gerard

[K C]

Hi Gerard,

I added a property node with some of the items you want to change. Can you try this ?

Message Edited by K C on 03-19-2007 10:20 AM